OLED material and application thereof

Abstract

The present application relates to the technical field of organic electroluminescent material, specifically relates to a kind of compound has the structure as follows formula (1): Wherein: X is hydrogen (H) or deuterium (D);R1 And R2 Each independently selected from hydrogen, cyano, substituted or unsubstituted C1~C12 Chain alkyl, substituted or unsubstituted C3~C12 Cycloalkyl, substituted or unsubstituted C6~C30 Aryl One of, or each independently represent the structure shown in formula Hy-1;D1 And D2 Each independently be the structure shown in formula Hy-1.The compound of the present application as the light-emitting layer material in OLED device, show excellent device performance and stability.The present application simultaneously protects the organic electroluminescent device using the above general compound.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent materials technology, specifically to a compound, a thermally activated delayed fluorescence material, an organic electronic light-emitting device containing the same, and their applications. Background Technology

[0002] Currently, optoelectronic devices using organic materials are becoming increasingly popular for several reasons. Many of the materials used in manufacturing these devices are relatively inexpensive, giving optoelectronic devices a potential cost advantage compared to inorganic devices. In the structure of organic electroluminescent devices for displays and lighting, blue fluorescence is typically combined with red and green phosphorescent materials. Recently, literature has reported fluorescent dye compounds based on benzonitrile and carbazole, known as TADF (Thermally Activated Delayed Fluorescence). These compounds utilize benzonitrile as an electron acceptor, with multiple carbazoles linked to the benzene ring as electron donors, exhibiting clearly separated HOMO and LUMO orbitals. For example:

[0003]

[0004] This type of material uses carbazole as an electron-donating group and introduces a large steric hindrance protecting group on the active site of carbazole, which helps to prevent Dexter energy transfer and suppress exciton quenching. However, the emission peak of this type of material is difficult to reach the deep blue light region, and it is often difficult to achieve high efficiency in deep blue light devices. In addition, the lifetime of this type of material is still relatively short. Due to these factors, it is difficult to achieve mass production and application of this type of material. Summary of the Invention

[0005] In view of this, the main objective of the present invention is to provide a compound, a thermally activated delayed fluorescence material, an organic electronic light-emitting device comprising the same, and its application, in order to at least partially solve the above-mentioned technical problems.

[0006] To achieve the above objectives, as a first aspect of the present invention, a compound having the structure of the following formula (1) is provided:

[0007]

[0008] In formula (1): X is hydrogen (H) or deuterium (D);

[0009] R1 and R2 are each independently selected from one of hydrogen, cyano, substituted or unsubstituted C1-C12 chain alkyl, substituted or unsubstituted C3-C12 cycloalkyl, substituted or unsubstituted C6-C30 aryl, or each independently represents the structure shown in formula Hy-1.

[0010] D1 and D2 are each independently the structure shown in equation Hy-1;

[0011]

[0012] In formula Hy-1: * indicates the connection site with the central benzene ring of the structure shown in formula (1);

[0013] Y1 is selected from single bonds, O, S, and CR. 3 R 4 NR 5 or SiR 6 R 7 One of them, the R 3 R 4 R 5 R 6 and R 7 Each is independently selected from one of hydrogen, C1-C12 chain alkyl, C3-C12 cycloalkyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl; preferred R 3 R 4 R 5 R 6 and R 7 Each is independently selected from one of the following: C1-C12 chain alkyl, C3-C12 cycloalkyl, substituted or unsubstituted C6-C30 aryl;

[0014] X 1 -X 8 Each is independently selected from C, CH, or N;

[0015] Ra and Rb are each independently selected from one of the following: substituted or unsubstituted C1-C12 chain alkyl, substituted or unsubstituted C3-C12 cycloalkyl, substituted or unsubstituted C1-C12 alkoxy, halogen, cyano, nitro, hydroxy, silyl, amino, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl, and Ra and Rb are not the same;

[0016] m is an integer from 0 to 4, preferably m is 1, 2 or 3;

[0017] n is an integer from 0 to 4, preferably n is 1, 2 or 3;

[0018] Furthermore, at least one hydrogen atom in the compound structure represented by formula (1) is deuterated;

[0019] When the aforementioned substituted or unsubstituted groups have substituents, the substituents are selected from one or more combinations of deuterium, halogen, C1-C12 chain alkyl, C3-C12 cycloalkyl, deuterated C1-C12 chain alkyl, deuterated C3-C12 cycloalkyl, C1-C12 alkoxy or thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl or fused-ring aryl, and C3-C30 monocyclic heteroaryl or fused-ring heteroaryl.

[0020] Preferably, in formula (1), X is hydrogen.

[0021] More preferably, in formula (1), R1 and R2 are both hydrogen, or R1 and R2 are each independently of the structure shown in Hy-1.

[0022] More preferably, formula Hy-1 has the structure shown in formula Hy-2 or Hy-3 as follows:

[0023]

[0024] In Hy-2 or Hy-3, Ra, Rb, X 1 -X 8 The definitions are the same as those in equation Hy-1.

[0025] More preferably, in formula Hy-1, Hy-2, or Hy-3, when Ra and Rb are each independently selected from C1-C10 chain alkyl or C3-C10 cycloalkyl, they are selected from the following structures:

[0026]

[0027] In a further preferred embodiment, in formula Hy-1, Hy-2, or Hy-3, Ra and Rb are each independently selected from hydrogen, methyl, isopropyl, tert-butyl, cyclohexyl, phenyl, 4-tert-butylphenyl, deuterated methyl, deuterated ethyl, deuterated isopropyl, deuterated tert-butyl, deuterated isobutyl, deuterated cyclopentyl, deuterated cyclohexyl, deuterated phenyl, or deuterated 4-tert-butylphenyl.

[0028] A further preferred embodiment of Hy-1 is the structure shown in equations X1 to X42 below:

[0029]

[0030] In a further preferred embodiment, in formula (1): R1 and R2 are each independently hydrogen or selected from any one of the formulas X1, X2, X3, X4, X5, X7, X8, X9, X12, X13, X14 or X16.

[0031] In this specification, the expression Ca to Cb represents that the group has a to b carbon atoms. Unless otherwise specified, the number of carbon atoms generally does not include the number of carbon atoms of the substituents.

[0032] In this specification, the way a ring structure is represented by "—" indicates that the connection point is located at any position on the ring structure where bonding can occur.

[0033] In this specification, the substituted or unsubstituted C6-C30 aryl group is preferably a C6-C20 aryl group, more preferably a group composed of phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthryl, indene, fluorenyl and their derivatives, fluoranyl, triphenylene, pyrene, perylene, etc. The group consisting of alkyl and tetraphenyl groups. Specifically, the biphenyl group is selected from 2-biphenyl, 3-biphenyl, and 4-biphenyl; the terphenyl group includes p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl, and m-terphenyl-2-yl; the naphthyl group includes 1-naphthyl and 2-naphthyl; the anthracene group is selected from 1-anthrayl, 2-anthrayl, and 9-anthrayl; the fluorenyl group is selected from 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, and 9-fluorenyl; the fluorenyl derivative is selected from 9,9'-dimethylfluorenyl, 9,9'-spirodifluorenyl, and benzo[a]fluorenyl; the pyrene group is selected from 1-pyrene, 2-pyrene, and 4-pyrene; and the tetraphenyl group is selected from 1-tetraphenyl, 2-tetraphenyl, and 9-tetraphenyl.

[0034] In this invention, heteroatoms generally refer to atoms or groups of atoms selected from N, O, S, P, Si and Se, preferably N, O and S.

[0035] In this specification, the substituted or unsubstituted C3-C30 heteroaryl group is preferably a C4-C20 heteroaryl group, more preferably a nitrogen-containing heteroaryl group, an oxygen-containing heteroaryl group, a sulfur-containing heteroaryl group, etc. Specific examples include: furanyl, thiophene, pyrrole, benzofuranyl, benzothiophene, isobenzofuranyl, indolyl, dibenzofuranyl, dibenzothiophene, carbazole and its derivatives, wherein the carbazole derivative is preferably 9-phenylcarbazole, 9-naphthylcarbazole, benzocarbazole, dibenzocarbazole, or indolocarbazole.

[0036] Furthermore, the compounds of general formula (1) of the present invention may preferably be one of the following specific structural compounds:

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051] The present invention also discloses the application of the compound described above in an organic electroluminescent device, preferably as a light-emitting layer in the organic electroluminescent device, and more preferably as a light-emitting dye and / or sensitizer in the light-emitting layer of the organic electroluminescent device.

[0052] The compounds of this invention described above exhibit thermally activated delayed fluorescence properties.

[0053] The present invention also discloses the application of the thermally activated delayed fluorescence material as described above in an organic electroluminescent device, preferably as a light-emitting layer in the organic electroluminescent device, and more preferably as a light-emitting dye and / or sensitizer in the light-emitting layer of the organic electroluminescent device.

[0054] The present invention also discloses an organic electroluminescent device, the organic electroluminescent device comprising a first electrode, a second electrode and one or more organic layers inserted between the first electrode and the second electrode, wherein the organic layer comprises at least one compound as described in the above general formula (1).

[0055] The present invention also discloses a display screen or display panel, wherein the display screen or display panel employs the organic electroluminescent device as described above; preferably, the display screen or display panel is an OLED display.

[0056] The present invention also discloses an electronic device having a display screen or display panel, wherein the display screen or display panel employs an organic electroluminescent device as described above.

[0057] The specific reasons for the excellent performance of the compounds of the present invention as light-emitting layer materials in organic electroluminescent devices are not yet clear, but it is speculated that the reasons may be as follows:

[0058] In this invention, the two substituents Ra and Rb in the general formula Hy-1 are structurally different. This is beneficial for increasing the rate of reverse intersystem crossing of the entire molecule, thereby making the TADF property of the compound more pronounced and thus improving the efficiency of organic electroluminescent devices using the compound. Furthermore, the compound preferably undergoes deuterium substitution at relatively reactive sites in its molecular structure, which helps to improve the stability of the compound. Detailed Implementation

[0059] The present invention will be described in detail below with several specific embodiments. The compounds of the present invention can be synthesized with reference to the specific synthesis examples shown below. However, it should be noted that obtaining the compounds is not limited to the synthesis methods and raw materials used in the present invention. Those skilled in the art can also select other methods or routes to obtain the novel compounds proposed in the present invention. The compounds for which synthesis methods are not mentioned in the present invention are all raw material products obtained through commercial means, or self-made using these raw material products according to known methods.

[0060] The solvents and reagents used in the synthesis examples, such as dichloromethane, petroleum ether, ethanol, tetrahydrofuran, N,N-dimethylacetamide, anhydrous magnesium sulfate, carbazole, benzimidazole, etc., can all be purchased from domestic chemical product markets, such as from Sinopharm Reagent Company, TCI Company, Shanghai Bid Pharmaceutical Company, and Bailingwei Reagent Company. Alternatively, those skilled in the art can also synthesize them using well-known methods.

[0061] The analysis and detection of synthetic intermediates and compounds were performed using an ABSCIEX mass spectrometer (4000QTRAP).

[0062] Representative synthetic pathways:

[0063]

[0064] Synthesis Example 1: Synthesis of S16

[0065]

[0066] Synthesis of intermediate S16-1:

[0067] 3-Deuterated methylcarbazole (50 g, 271.36 mmol) and 500 mL of DMF were added to a 2000 mL three-necked flask. Under nitrogen protection, the mixture was stirred and cooled to -20 °C with liquid nitrogen and ethanol. N-bromosuccinimide (16.98 g, 298.5 mmol) was dissolved in 100 mL of DMF and slowly added dropwise to the reaction mixture using a constant pressure dropping funnel. The mixture was stirred for 2 hours. The reaction mixture was poured into 1000 mL of water and extracted twice with 1000 mL of dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated. The mixture was then subjected to silica gel column chromatography (PE:DCM = 10:1). 69.21 g of a white solid was obtained, with a yield of 96%. The molecular ion mass determined by mass spectrometry was 263.14 (theoretical value: 263.15).

[0068] Synthesis of intermediate S16-2:

[0069] In a 2000 ml three-necked flask, add S16-1 (60 g, 228 mmol), 4-deuterated methyl-2,3,5,6-tetradeuterated phenylboronic acid (35.87 g, 250.81 mmol), tetratetraphenylphosphine palladium (2.63 g, 2.28 mmol), potassium carbonate (63.02 g, 456.01 mmol), 1,4-dioxane (500 ml), and water (100 ml). Replace the nitrogen atmosphere, stir, and heat to 110 °C for 5 hours. Stop heating, cool the reaction solution, filter the solution through 100-200 mesh silica gel, evaporate the filtrate to dryness, and perform silica gel column chromatography (PE:DCM = 10:1) to obtain 58.77 g of white solid, yield 92%. Mass spectrometry analysis determined the molecular particle mass to be 281.42 (theoretical value: 281.42).

[0070] Synthesis of compound S16:

[0071] In a 2000 ml three-necked flask, S16-2 (50 g, 177.67 mmol), 2,6-difluorobenzonitrile (11.12 g, 79.95 mmol), potassium carbonate (36.83 g, 266.50 mmol), and 500 ml of DMF were added. The mixture was purged with nitrogen, stirred, and heated to 90 °C for 12 hours. Heating was then stopped, and the reaction solution was poured into water and filtered to obtain 69 g of a white crude product. Silica gel stirred column chromatography (PE:DCM = 10:1) yielded 55.11 g of a white solid, with a yield of 92%. Mass spectrometry analysis determined the molecular particle mass to be 661.94 (theoretical value: 661.94).

[0072] Synthesis Example 2: Synthesis of S51

[0073]

[0074] Synthesis of intermediate S51-1:

[0075] In a 2000 ml three-necked flask, 3-bromo-6-deuterated carbazole (50 g, 202.34 mmol), pentadeuterated phenylboronic acid (28.26 g, 222.57 mmol), tetrakis(triphenylphosphine)palladium (2.34 g, 2.02 mmol), potassium carbonate (55.93 g, 404.67 mmol), 1,4-dioxane (500 ml), and water (100 ml) were added. The mixture was purged with nitrogen, stirred, and heated to 110 °C for 5 hours. Heating was stopped, and the reaction solution was cooled. The solution was filtered through 100-200 mesh silica gel, and the filtrate was evaporated to dryness. The solution was then subjected to silica gel column chromatography (PE:DCM = 10:1) to obtain 46.86 g of a white solid, with a yield of 87%. The molecular particle mass determined by mass spectrometry was 265.39 (theoretical value: 265.38).

[0076] Synthesis of compound S51:

[0077] S51-1 (40 g, 142.13 mmol), 2,3,6-trifluorobenzonitrile (7.37 g, 46.90 mmol), cesium carbonate (69.47 g, 212.20 mmol), and DMF were added to a 2000 ml three-necked flask. The mixture was then purged with nitrogen in 500 ml of water, stirred, and heated to 90 °C for 12 hours. Heating was stopped, and the reaction solution was poured into water and filtered to obtain 42 g of a yellow crude product. Silica gel stirred column chromatography (PE:DCM = 10:1) yielded 37.13 g of a white solid, with a yield of 93%. Mass spectrometry analysis determined the molecular particle mass to be 845.10 (theoretical value: 845.11).

[0078] Synthesis Example 3: Synthesis of S91

[0079]

[0080] Synthesis of compound S91:

[0081] In a 2000 ml three-necked flask, 41.99 g of 3-deuterated tert-butyl-6-deuterated carbazole (179.91 mmol), 7 g of 2,3,5,6-trifluorobenzonitrile (39.98 mmol), 78.16 g of cesium carbonate (239.88 mmol), and 500 ml of DMF were added. The atmosphere was replaced with nitrogen, and the mixture was stirred and heated to 90 °C for 12 hours. Heating was then stopped, and the reaction solution was poured into water and filtered to obtain 45 g of a white crude product. Silica gel stirred column chromatography (PE:DCM = 10:1) yielded 38.58 g of a yellow solid, with a yield of 94%. The molecular particle mass determined by mass spectrometry was 1028.58 (theoretical value: 1028.58).

[0082] Synthesis Example 4: Synthesis of S125

[0083]

[0084] Synthesis of intermediate S125-1:

[0085] 2,3,5,6-trifluorobenzonitrile (10 g, 57.11 mmol) and potassium carbonate (31.57 g, 228.46 mmol) were added to a 1000 ml three-necked flask. The flask was purged with nitrogen, and 200 ml of DMF was added. The mixture was stirred and heated to 90 °C. 3-Deuterated methyl-6-deuterated carbazole (21.16 g, 114.23 mmol) was dissolved in 100 ml of DMF and slowly added dropwise to the reaction mixture. After the addition was complete, the reaction was allowed to proceed for 12 hours. Heating was then stopped, and the reaction solution was poured into water and filtered to obtain 30 g of a yellow crude product. Silica gel stirred column chromatography (PE:DCM = 10:1) yielded 19.71 g of a yellow solid, with a yield of 68%. The molecular particle mass determined by mass spectrometry was 505.61 (theoretical value: 505.60).

[0086] Synthesis of compound S125:

[0087] S149-1 (19 g, 37.58 mmol), 3-deuterated phenyl-6-deuterated carbazole (18.74 g, 75.16 mmol), and cesium carbonate (48.98 g, 150.32 mmol) were added to a 1000 ml three-necked flask. Nitrogen gas was purged, and 200 ml of DMF was added. The mixture was stirred and heated to 90 °C for 12 hours. Heating was stopped, and the reaction solution was poured into water. The mixture was filtered to obtain 43 g of a yellow crude product. Silica gel stirred column chromatography (PE:DCM = 10:1) yielded 33.12 g of a yellow solid, with a yield of 91%. The molecular particle mass determined by mass spectrometry was 964.28 (theoretical value: 964.28).

[0088] Synthesis Example 5: Synthesis of S131

[0089]

[0090] Synthesis of intermediate S131-1:

[0091] 2,3,5,6-trifluorobenzonitrile (10 g, 57.11 mmol) and potassium carbonate (47.36 g, 342.69 mmol) were added to a 1000 ml three-necked flask. The flask was purged with nitrogen, and 200 ml of DMF was added. The mixture was stirred and heated to 90 °C. 3-Deuterated tert-butyl-6-deuterated carbazole (43.99 g, 188.48 mmol) was dissolved in 100 ml of DMF and slowly added dropwise to the reaction system. After the addition was complete, the reaction was allowed to proceed for 12 hours. Heating was then stopped, and the reaction solution was poured into water and filtered to obtain 49 g of a yellow crude product. Silica gel stirred column chromatography (PE:DCM = 10:1) yielded 37.81 g of a yellow solid, with a yield of 81%. The molecular particle mass determined by mass spectrometry was 815.22 (theoretical value: 815.21).

[0092] Synthesis of compound S131:

[0093] S155-1 (30 g, 36.80 mmol), 3-deuterated phenyl-6-deuterated carbazole (10.09 g, 40.48 mmol), and cesium carbonate (23.98 g, 73.60 mmol) were added to a 1000 ml three-necked flask. Nitrogen gas was purged, and 200 ml of DMF was added. The mixture was stirred and heated to 90 °C for 12 hours. Heating was stopped, and the reaction solution was poured into water. The mixture was filtered to obtain 44 g of a yellow crude product. Silica gel stirred column chromatography (PE:DCM = 10:1) yielded 35.61 g of a yellow solid, with a yield of 93%. The molecular particle mass determined by mass spectrometry was 1044.55 (theoretical value: 1044.55).

[0094] Based on the same inventive concept, embodiments of the present invention also provide an organic light-emitting device comprising the compounds of the above embodiments. The following example uses an OLED as an organic light-emitting device for illustration; however, it should be understood that the following detailed description is not a limitation of the present invention, and those skilled in the art can extend the application of the following detailed description to other organic light-emitting devices.

[0095] In one embodiment, the OLED includes a first electrode and a second electrode, and an organic material layer located between the electrodes. This organic material layer can be further divided into multiple regions. For example, the organic material layer may include a hole transport region, a light-emitting layer, and an electron transport region.

[0096] In specific embodiments, a substrate can be used below the first electrode or above the second electrode. The substrate is typically made of glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. Furthermore, thin-film transistors (TFTs) can also be incorporated into the substrate used for displays.

[0097] The first electrode can be formed by sputtering or depositing the material to be used as the first electrode on a substrate. When the first electrode is used as the anode, transparent conductive oxide materials such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), and zinc oxide (ZnO) and any combination thereof can be used. When the first electrode is used as the cathode, metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), and magnesium-silver (Mg-Ag) and any combination thereof can be used.

[0098] Organic material layers can be formed on electrodes using methods such as vacuum thermal evaporation, spin coating, and printing. The compounds used as organic material layers can be small organic molecules, large organic molecules, polymers, and combinations thereof.

[0099] The hole transport region is located between the anode and the emissive layer. The hole transport region can be a single-layer hole transport layer (HTL), including single-layer hole transport layers containing only one compound and single-layer hole transport layers containing multiple compounds. Alternatively, the hole transport region can be a multilayer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL); wherein the HIL is located between the anode and the HTL, and the EBL is located between the HTL and the emissive layer.

[0100] The material for the hole transport region may be selected from, but is not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives as shown in HT-1 to HT-50 below; or any combination thereof.

[0101]

[0102]

[0103]

[0104]

[0105] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can be one or more compounds of HT-1 to HT-50 described above, or one or more compounds of HI-1 to HI-3 described below; it can also be one or more compounds of HT-1 to HT-51 doped with one or more compounds of HI-1 to HI-3 described below.

[0106]

[0107] The emissive layer includes luminescent dyes (i.e., dopants) that can emit different wavelengths of light, and may also include a host material. The emissive layer can be a monochromatic emissive layer emitting a single color such as red, green, or blue. Multiple monochromatic emissive layers of different colors can be arranged in a planar pattern according to pixel design, or they can be stacked together to form a colored emissive layer. When different colored emissive layers are stacked together, they can be separated from each other or connected to each other. The emissive layer can also be a single colored emissive layer that can simultaneously emit different colors such as red, green, and blue.

[0108] Depending on the technology used, the light-emitting layer material can be various, including fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescence materials. An OLED device can employ a single light-emitting technology or a combination of different technologies. These different light-emitting materials, categorized by technology, can emit light of the same color or different colors.

[0109] In one aspect of the invention, the light-emitting layer employs fluorescent electroluminescence technology. The fluorescent host material of the light-emitting layer may be selected from, but is not limited to, one or more combinations of BFH-1 to BFH-17 listed below.

[0110]

[0111] In one aspect of the invention, the light-emitting layer employs fluorescent electroluminescence technology. The fluorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of BFD-1 to BFD-25 listed below.

[0112]

[0113]

[0114] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The main material of the light-emitting layer is selected from, but not limited to, one or more combinations of GPH-1 to GPH-80.

[0115]

[0116]

[0117]

[0118]

[0119]

[0120] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0121]

[0122]

[0123]

[0124] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0125]

[0126]

[0127] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of YPD-1 to YPD-11 listed below.

[0128]

[0129] In one aspect of the invention, the light-emitting layer employs thermally activated delayed fluorescence emission technology. The main material of the light-emitting layer is selected from, but not limited to, one or more combinations of PH-1 to PH-85.

[0130] In one aspect of the present invention, an electron blocking layer (EBL) is located between the hole transport layer and the light-emitting layer. The electron blocking layer may employ, but is not limited to, one or more compounds of HT-1 to HT-51 described above, or one or more compounds of PH-47 to PH-77 described above; or a mixture of one or more compounds of HT-1 to HT-51 and one or more compounds of PH-47 to PH-77 may be employed.

[0131] The OLED organic material layer may also include an electron transport region between the light-emitting layer and the cathode. The electron transport region can be a single-layer electron transport layer (ETL), including single-layer electron transport layers containing only one compound and single-layer electron transport layers containing multiple compounds. Alternatively, the electron transport region can be a multilayer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0132] In one aspect of the present invention, the electron transport layer material may be selected from, but not limited to, one or more combinations of ET-1 to ET-65 listed below.

[0133]

[0134]

[0135]

[0136] In one aspect of the present invention, a hole blocking layer (HBL) is located between the electron transport layer and the light-emitting layer. The hole blocking layer may employ, but is not limited to, one or more compounds of ET-1 to ET-65, or one or more compounds of PH-1 to PH-46; or a mixture of one or more compounds of ET-1 to ET-65 and one or more compounds of PH-1 to PH-46 may be employed.

[0137] The device may also include an electron injection layer located between the electron transport layer and the cathode, and the electron injection layer material includes, but is not limited to, one or more combinations of the following.

[0138] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Mg.

[0139] Device Example 1

[0140] The fabrication process of the organic electroluminescent device in this embodiment is as follows:

[0141] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a acetone:ethanol mixed solvent, baked in a clean environment until all moisture was removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0142] The glass substrate with the anode was placed in a vacuum chamber and evacuated to <1×10⁻⁵ Pa. On the anode film, a 10 nm HT-4:HI-3 (97 / 3, w / w) mixture was vacuum thermally deposited in the following order: as a hole injection layer, a 60 nm HT-4 compound as a hole transport layer, and a 5 nm HT-51 compound as an electron blocking layer; a 40 nm PH-54:S91:BDF-16 (100:40:1, w / w / w) ternary mixture was deposited as a light-emitting layer; a 5 nm PH-28 compound as a hole blocking layer; a 25 nm ET-61:ET-57 (50 / 50, w / w) compound as an electron transport layer; a 1 nm LiF compound as an electron injection layer; and a 150 nm aluminum electrode as a cathode. The total deposition rate of all organic layers and LiF was controlled at 0.1 nm / s, and the deposition rate of the metal electrode was controlled at 1 nm / s.

[0143] Device Examples 2-6 were fabricated using the same method as Example 1, except that the compound S91 of the present invention in the light-emitting layer was replaced with compounds S125, S89, S90, S127, and S131 of the present invention, respectively.

[0144] Comparative Examples 1-3 were fabricated using the same method as in Device Example 1, except that the compound S91 of the present invention in the light-emitting layer was replaced with compounds C1, C2 and C3 in the prior art, respectively.

[0145]

[0146] Quantum chemical calculations were performed on the C1-C3 compounds of the prior art used in the comparative examples and on the S89, S90, S91 and S125 of the present invention used in the examples. The specific calculation data are shown in Table 1.

[0147] Table 1:

[0148]

[0149] As can be seen from Table 1 above, compounds S89, S90, S91, and S125 of the present invention have higher singlet and triplet energy levels compared to the comparative compound C3, and can be used in deep blue OLED devices. However, compounds C2 and C3 have too low singlet energy levels to meet the requirements of deep blue OLED devices.

[0150] The organic electroluminescent devices prepared by the above process were subjected to the following performance measurements:

[0151] Under the same brightness, the driving voltage, current efficiency, and lifetime of organic electroluminescent devices prepared from the compound and comparative materials were determined using a digital source meter and luminance meter. Specifically, the voltage was increased at a rate of 0.1 V per second, and the measurement was performed when the brightness of the organic electroluminescent device reached 1000 cd / m². 2 The voltage at that time is the driving voltage, and the current density at that time is measured simultaneously; the ratio of brightness to current density is the current efficiency; the life test of LT95 is as follows: using a luminance meter at 1000 cd / m² 2 At a constant current, the brightness of the organic electroluminescent device decreased to 950 cd / m² under the specified brightness. 2 The time is expressed in hours. The lifespan of Comparative Example 1 is taken as Standard 1, and the others are ratios to it.

[0152] The performance of the organic electroluminescent devices prepared in Examples 1-6 and Comparative Examples 1-3 is shown in Table 2 below.

[0153] Table 2:

[0154]

[0155]

[0156] As shown in Table 2 above, when doped with the same deep blue fluorescent dye BFD-16, compared to Comparative Examples 2 and 3 which used compounds C2 and C3 as host materials respectively, the devices prepared in Examples 1-6 using the compounds of this invention as host materials all had emission peak wavelengths in the deep blue region. This is because the compounds of this invention do not have substituents at the para-cyano group, thus regulating the emission wavelength in the deep blue region, which can effectively transfer energy to the deep blue dye. In contrast, compounds C2 and C3 have lower triplet energy levels, and energy cannot be completely transferred to the dye in the device, thus exhibiting self-luminescence of C2 and C3, resulting in emission in the sky blue region. This indicates that C2 and C3 cannot meet the requirements of deep blue OLED devices. Compared to the device prepared in Comparative Example 1, which used compound C1 with emission in the deep blue region, the devices prepared in Examples 1-6 using the compounds of this invention showed improved lifetime and excellent device performance. This may be because different substituent groups are used on both sides of the carbazole in the compound structure of the present invention. While protecting the active site of the compound, some of the more reactive hydrogen atoms are deuterated, which improves the stability of the compound and increases the lifespan of the device.

[0157] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. Compounds having the following structures, 。 2. An organic electroluminescent device, comprising a first electrode, a second electrode, and one or more organic layers inserted between the first electrode and the second electrode, characterized in that, The organic layer includes at least one compound as described in claim 1.

3. An organic electroluminescent device, comprising an anode layer, a plurality of light-emitting functional layers, and a cathode layer; wherein the plurality of light-emitting functional layers include at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, and an electron transport layer formed sequentially, wherein the hole injection layer is formed on the anode layer, and the cathode layer is formed on the electron transport layer; wherein, The light-emitting layer contains the organic compound as described in claim 1.

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